The present invention relates to a method of treating a semiconductor material to influence its carrier concentration and carrier lifetime, as well as a semiconductor material produced by the method. II-VI semiconductor materials, such as CdTe, have been used in a variety of applications, such as photovoltaics, infrared detectors, and focal plane arrays. For example, laboratory experiments have demonstrated CdTe photovoltaic (PV) cells having an efficiency of 21%. However, it would be advantageous to improve this efficiency, in order to reduce the costs of energy produced by CdTe PV cells.